One of life's mysteries, explained

Much angst in the Bay Area over the Giants, who, after two championships in three years, are not winning games.  Many opinions expressed on radio, but I have noticed two things that I think might be relevant:

#1 - They have a mediocre offense.  The Giants are scoring 4.0 runs per game, vs. the League average of 4.1.  There is talk of signing more hitters.

#2 - Their pitching, the basis of their two championships, has fallen apart.  The Giants have given up 4.5 runs per game this year, vs. the League average of 4.1.  Oddly, there's not much talk of signing up some pitchers who are good.  But the starting staff is a disaster.  Pitching in one of the friendliest parks in the majors, here are the ERAs of their starters, (this year / career):

• Matt Cain (4.9/3.4) - Just signed a huge long-term contract
• Madison Bumgarner (3.1/3.2) - Your basic left-handed horse
• Tim Lincecum (4.7/3.4, after 5.2 in 2012) - Flamed out, alas
• Barry Zito (4.4/4.0) - Has improved a bit in the final year of his huge long-term contract
• Ryan Vogelsong (7.2/4.5) - Injured after nine starts

Just to sum up, they have one starter who is pitching better than his career ERA, and one starter who is below the League's ERA of 3.8.

It's not complicated:  that's not going to get it done, son.